Posted: Yesterday at 23:32
I'm familiar with this trouble. In fact I've got it in both ankles at the moment.
You should ease off the intensity of your training, in particular avoid speedwork and especially downhills.
Is the area around the achilles tendon spongy? if so I'm afraid getting back to normal is going to be a long haul. If you know a sports injury therapist I would recommend deep tissue massage. Otherwise it is a matter of regular icing, especially after exercise, and for the rest of the time keeping the area warm. Do frequent stretches (when warm) which would include standard calf stretches leaning against a wall and heel dips off a step.
A short term solution, especially if you have a race coming up, is to put heel inserts in your shoes to raise the heel a bit and prevent the tendon getting aggravated in the same place by the back of the shoe. Something I find very helpful, but it's drastic, is to cut down the v-notch at the back of the shoe further with a knife. This takes a lot of pressure off the achilles but probably shortens shoe life!
I wish I knew what the cause of this common runner's injury was, but I don't. The main suspect, I think, is the back of the shoe aggravating the tendon especially on steep/offroad descents.